The transducer of Doppler sonography produces a ultrasound with frequency 7.5 MHz and its placed above the artery in the patients body. Aome of the ultrasound bounces back form the blood flowing in the vessel and returns back to the transducer that can detect the returning ultrasound signal. When it bounces of blood, the blood can be sen as a moving ultrasound sourve that emits the ultrasound with the same frequency of 7.5 MHz. However, the apparent frequency that the detector in the transducer as a staionary observer Speed of sound is in human body 15oo m/s (a) If the frequency detected in the transducer shifts by 550 Hz (the apparent frequency = 7500550 Hz), what is the speed of the blood flow in the artery? Assume that the blood flows toward the transducer. ( (b) The speed of the blood flow slows down when stenosis is present in the blood vessel. If the detector receives ultrasound frequency shifted by 250 Hz (the apparent frequency = 7500250 Hz), what is the speed of the blood flow? Assume that the blood flows toward the transducer. (c) What frequency does the detector receives if the same spot in the blood vessel as in part (b) but the transducer is placed so that the blood flows away from the transducer? (d) If the transducer receive a signal with negative shift in the frequency by 3000 Hz (the apparent frequency = 7497000 Hz), what is the magnitude and direction of the blood flow in that specific spot? Answer the direction as toward or away from the transducer.
Properties of sound
A sound wave is a mechanical wave (or mechanical vibration) that transit through media such as gas (air), liquid (water), and solid (wood).
Quality Of Sound
A sound or a sound wave is defined as the energy produced due to the vibrations of particles in a medium. When any medium produces a disturbance or vibrations, it causes a movement in the air particles which produces sound waves. Molecules in the air vibrate about a certain average position and create compressions and rarefactions. This is called pitch which is defined as the frequency of sound. The frequency is defined as the number of oscillations in pressure per second.
Categories of Sound Wave
People perceive sound in different ways, like a medico student takes sound as vibration produced by objects reaching the human eardrum. A physicist perceives sound as vibration produced by an object, which produces disturbances in nearby air molecules that travel further. Both of them describe it as vibration generated by an object, the difference is one talks about how it is received and other deals with how it travels and propagates across various mediums.
The transducer of Doppler sonography produces a ultrasound with frequency 7.5 MHz and its placed above the artery in the patients body. Aome of the ultrasound bounces back form the blood flowing in the vessel and returns back to the transducer that can detect the returning ultrasound signal. When it bounces of blood, the blood can be sen as a moving ultrasound sourve that emits the ultrasound with the same frequency of 7.5 MHz. However, the apparent frequency that the detector in the transducer as a staionary observer Speed of sound is in human body 15oo m/s
(a) If the frequency detected in the transducer shifts by 550 Hz (the apparent frequency = 7500550 Hz), what is the speed of the blood flow in the artery? Assume that the blood flows toward the transducer. (
(b) The speed of the blood flow slows down when stenosis is present in the blood vessel. If the detector receives ultrasound frequency shifted by 250 Hz (the apparent frequency = 7500250 Hz), what is the speed of the blood flow? Assume that the blood flows toward the transducer.
(c) What frequency does the detector receives if the same spot in the blood vessel as in part (b) but the transducer is placed so that the blood flows away from the transducer?
(d) If the transducer receive a signal with negative shift in the frequency by 3000 Hz (the apparent frequency = 7497000 Hz), what is the magnitude and direction of the blood flow in that specific spot? Answer the direction as toward or away from the transducer.
given data,
source is blood which is moving and the transducer is the stationary observer.
frequency emitted by source, n = 7.5 MHz = 7500000 Hz
speed of sound in human body, v = 1500 m/s
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